You can receive Skype calls while other apps are running on your iPhone or iPod Touch. During a call, you might want to check movie listings, read email or play with other apps. Your iPhone will ring if you get a Skype call, even if the app isn’t running.

Skype has been full of upgrades lately. In May, they introduced an iPhone app that lets users make calls over their 3G cellular connections, without being in range of Wi-Fi.

Multitasking requires an iPhone 4, iPhone 3GS, or a third-generation iPod touch (32GB and 64GB models from late 2009). More details here.

StreetSmartMeeting.com is a free conference call service with some extras. It includes a calendar tool that generates invitations to your meeting and provides reminders for group calls. In the past, we’ve missed a lot of conference calls.

Calls are secure and may be recorded and stored for playback for up to 90 days. The service also gives you a free permanent meeting call number, so you can have impromptu calls with colleagues and friends without the hassle of setting up a group call.  For a fee, you can also store files that can be shared with your meeting participants, as long as they have an Internet connection. You can allow them to just view the files or edit them.

Google Voice is free for everyone. Starting today, you no longer need an invitation.

Google Voice gives you a special phone number that routes calls to all your phones. You could be at your castle in Scotland, your other castle in Spain, at your desk at work, or at home with Mom. You’ll still get the call.

It also gives you voicemail, call forwarding, teleconferencing, call screening, etc. Go to Google.com/voice.

Calls between Skype users are free anywhere in the world, but calling non-Skype users are not. Those calls are now 60 percent cheaper. Prices start at U.S. $1.09 a month for calls to 170 countries.  You don’t have to sign up for more than one month to get the $1.09 rate.

In other Skype news, free video calling with up to five people participating is now available. More info at Skype.com.

Skype is offering free connections this week through a feature called “Skype Access.” You can connect to the Internet in over 100,000 hotspots around the world starting today through Friday, April 23 — including most international airports.

That’s a stingy offer, but it’s a good way to try out Skype Access, which is a new feature  that lets anyone pay for WiFi access using Skype credit, which you buy in advance at Skype.com. Just select an available public access WiFi network from the list that pops up on your computer screen and Skype will pop up offering to use your credit balance.  When the free period is over, the cost is 19 cents a minute.

For a list of compatible WiFi networks, visit http://bit.ly/9OreVE. Unfortunately, it only works on Windows and Mac computers, not the new iPad.

In the U.S. there are over 54 million users of prepaid phones, an increase of 17 percent over the last year. Regular, contract-type cell phone usage only grew 3 percent over the same period. We wouldn’t think this augurs well for companies that provide cell phone service..

We were curious about what is probably the best-selling prepaid phone in the U.S., the “TracFone.” We bought two of them at our local grocery store for $10 each. One was missing its battery, making it worthless, and we tossed it. (At these prices, what are you going to do, complain to the company and see if they believe you?)

These phones are dirt cheap. You get 10 minutes of calling time when you buy the phone, and for another $20, you can have 60 minutes more for another 90 days, and so on. The phone comes with a calculator, stop watch, voice mail, call waiting, caller ID, etc., and lets you send three text messages for each minute of air time. Except for being cheated by buying one that had no battery, we found everything worked satisfactorily.

Another cheap way to go is T-Mobile. They have a wide range of phones, starting with a $20 Nokia phone that includes an FM radio. (We figure that’s so you can tune in the news to find out why your phone isn’t connecting.) Some of the T-Mobile prepaid phones even have cameras. Adding talk time, starts at $10 for 30 minutes. An even cheaper service charges you just $1 for unlimited talk only on the days you use the phone. (That would certainly work for us: we started about 12 years ago with an expensive cell phone and ended up making only three calls in four years.) There are great reviews of prepaid phones at PrepaidReviews.com and Compare-prepaid-cell-phones.com. The latter site has codes you can use to get discounts.

The service will be available on six Blackberrys – the Storm, Storm2, Curve 8330, Curve 8530, 8830 World Edition and the Tour, as well as the Motorola Droid, Droid Eris and Motorola Devour.

Apparently, Verizon execs feel that they are making so much money from ordinary text messaging that they aren’t worried about the loss of cell phone calling minutes.  But what happens if regular text messages are replaced by Skype-to-Skype messaging?

Recently, we read about a girl who had to have surgery for carpal tunnel syndrome because she sent 4,000 messages a month.  Since cost won’t be much of a factor on these Skype-enabled phones, expect to read more stories like this. Unless with  free phone calling, people  go back to calling instead of texting.

Zdnet has more info on Skype Mobile here.

To use BigVoiceMail, you need a microphone attached to your computer. Most laptops have one built in. Open the software, click “record,” then “stop,” then “mail.” Your voice message is sent as an attachment to a message. You can also do it by clicking the space bar three times – very useful for the blind. The message files are compressed. A one-minute message takes up only 360 kilobytes, a small amount these days. Even an eight-and-a-half minute message is less than three megabytes.

BigVoiceMail is free for 10-second messages. For longer messages, you need the pro version, for $15.

If you’re also tired of paying for this kind of non-service, rest assured: you’re not alone. The number of people who use Skype, which lets you make free phone calls as long as you have an Internet connection, is growing. Skype’s share of international calling minutes climbed to 12 percent in 2009, compared with 8 percent in 2008, according to the research firm TeleGeography.

New data from TeleGeography also show that the growth of international telephone traffic has slowed slightly, while Skype’s growth has accelerated. Over the past 25 years, international call volume from telephones has grown at a compounded annual rate of 15 percent. But in the past two years, international telephone traffic growth has slowed to only 8 percent.

The Internet and its consequent ability to permit free phone calling has completely changed the telephone business. Cell phone now accounts for most local calls.  AT&T, America’s oldest phone company, said recently that it wants to get out of the “landline” business. Landlines refer to the copper wiring that connects older telephones to large switching systems that physically transfer calls between numbers. This used to be done by actual operators seated at switchboards and you can see this sometimes in old movies. It’s too expensive now.

The deep recession has had a marked impact on many routes. Traffic to Mexico, the world’s largest calling destination, declined 4 percent in 2008, and aggregate traffic to Central America has declined 5 percent. You can get more information about Skype and sign up at Skype.com. By the way, you can also make Internet phone calls with Apple’s new iPad.

New TVs coming out soon from LG and Panasonic will let you make free Skype video phone calls. The Panasonic TVs will come in sizes ranging up to 65 inches (that’s BIG). LG Electronics will sell 26 styles of Skype-enabled TVs.  Both parties have to have webcams attached for this to work. Make sure your hair is combed.

These new high-definition TVs will let you call landline phones, receive voicemail (for an extra fee), talk to 24 people at once, and receive and make regular or video calls. Your TV program will pause while you make a call. For more info, go to skype.com/go/TV